Some of the world's most incredible engineering projects are now deserted. Revisit a Soviet megastructure, a massive Nazi brainwashing complex, and a dangerous desert pass. How were they built? Why were they mysteriously abandoned?

Some of the world's most incredible engineering projects are now deserted. Explore a ghost town that was once a dangerous industrial hellscape, a giant warship at the bottom of the ocean, and a top secret relic from the Cold War.

The events that took place in a town outside Chernobyl are explored.

The stories behind a massive military site and more are explored.

A strange Cuban prison, an eerie escape route built for Armageddon, and an underwater marvel that changed history are mysterious deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.

A mysterious American pyramid built out of Cold War paranoia, a haunted prison, and a cluster of structures in the Atlantic are mysterious deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.

Uncover the secrets of Nazi engineering projects that lie in ruins. These deserted places are home to extraordinary mysteries and untold secrets, and we revisit them to understand how they were built, and why they were abandoned.

Uncover the secrets of Soviet engineering projects that now lie in ruins. These deserted places are home to extraordinary mysteries and secrets, and we revisit them to understand how they were built, and why they were abandoned.

Traces of a Russian hole to hell in the Arctic, a military base in America's wild west, and a strange looming tower are mysterious deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.

A secret Russian military base in the Gobi Desert, a strange complex in an American wasteland, and a relic high atop a mountain are mysterious deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.

Uncover the secrets of American engineering projects that now lie in ruins. These deserted places are home to extraordinary mysteries and secrets, and we revisit them to understand how they were built, and why they were abandoned.

Uncover the secrets of military engineering projects that now lie in ruins. These deserted places are home to extraordinary mysteries and secrets, and we revisit them to understand how they were built, and why they were abandoned.

A secret structure on a sinister mountain, an industrial compound swallowed by a forest, and a mysterious run in a sand dune are strange deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.

A strange alien shrine on a mountain peak, a bridge built in the Alaskan wilderness, and an American castle with a dangerous secret are mysterious deserted engineering projects. New discoveries reveal how they were built and why they were abandoned.

An American ghost town in the Amazon jungle, a secret Nazi base, and a deadly concrete fortress 866 miles long are mysterious deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.

A terrifying sea fortress, a highway in the Amazon that suddenly vanishes, a mysterious structure in the shadow of the Statue of Liberty are deserted engineering projects, and new discoveries reveal how they were built and why they were abandoned.